2007 ISUZU KB P190 oil

3B-4 POWER-ASSISTED STEERING SYSTEM
General Description
The hydraulic power steering system consists of a
pump, an oil reservoir, a steering unit, a pressure hose
and a return hose.

Power Steering Unit

440R300001
The power steering unit is a rack and pinion type.
The toe-in angle can be adjusted by turning the rod on
each side.
The steering housing cannot be disassembled.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

POWER-ASSISTED STEERING SYSTEM 3B-5
Hydraulic Pump
4JJ1-TC, 4JK1-TC




RTW 53BMF0003
The hydraulic pump is vane-type design. The
submerged pump has a housing and internal parts that
are inside the reservoir and operate submerged in oil.
There are two bore openings at the rear of the pump
housing. The larger opening contains the cam ring,
pressure plate, thrust plate, rotor and vane assembly,
and end plate. The smaller opening contains the
pressure line union, flow control valve and spring.
The flow control orifice is part of the pressure line union.
The pressure relief valve inside the flow control valve
limits the pump pressure.



BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

POWER-ASSISTED STEERING SYSTEM 3B-7
Power Steering System Test
Test Procedure
F02RX002
Legend
(1) Bolt
(2) Hose
(3) Power Steering Unit
(4) Power Steering Pump


The fluid pressure test in the power steering system is
performed to determine whether or not the oil pump and
power steering unit are functioning normally.
The power steering system test is used to identify and
isolate hydraulic circuit difficulties. Prior to performing
this test, the following inspections and corrections, i
f
necessary, must be made.
・ Inspect pump reservoir for proper fluid level.
・ Inspect pump driver gear condition.
1. Place a container under the pump to catch the fluid when disconnecting or connecting the hoses.
2. W ith the engine NOT running, disconnect the
pressure hose at the power steering pump and
install power steering tester 5-8840-0135-0 and
power steering tester adapter 5-8840-2297-0 as
shown in the illustration. The gage must be between
the shutoff valve and pump. Open the shutoff valve.
3. Check the fluid level. Fill the reservoir with powe
r
steering fluid, to the "Full" mark. Start the engine,
then turn the steering wheel and momentarily hold it
against a stop (right or left). Turn the engine off and
check the connections at tester for leakage.
4. Bleed the system. Refer to Bleeding the Powe
r
Steering System in this section.
5. Start the engine and check the fluid level. Add power steering fluid if required. W hen the engine is
at normal operating temperature, increase engine
speed to 1500 rpm.
CAUTION: Do not leave shutoff valve fully closed
for more than 5 seconds, as the pump could
become damaged internally.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

3B-8 POWER-ASSISTED STEERING SYSTEM
6. Fully close the shutoff valve. Record the highest
pressures.
・ If the pressure recorded is within 9800-10300 kPa
(100-105 kg/cm
2/1422-1493psi), the pump is
functioning within its specifications.
・ If the pressure recorded is higher than 10300 kPa
(105 kg/cm
2/1493psi), the valve in the pump is
defective.
・ If the pressure recorded is lower than 9800 kPa
(100 kg/cm
2/1422psi), the valve or the rotating
assembly in the pump is defective.
7. If the pump pressures are within specifications, leave the valve open and turn (or have someone
else turn) the steering wheel fully in both directions.
Record the highest pressures and compare with the
maximum pump pressure recorded in step 6. If this
pressure cannot be built up at either side of the
power steering unit, the power steering unit is
leaking internally and must be replaced.
8. Shut the engine off, remove the testing gauge.
9. Reconnect the pressure hose, check the fluid level and make the needed repairs.
10. If the problem still exists, the steering and front suspension must be thoroughly examined.

Maintenance
The hydraulic system should be kept clean, the fluid
level in the reservoir should be checked at regula
r
intervals and fluid added when required. Refer to
Recommended Fluids and Lubricants in General
Information section for the type of fluid to be used and
the intervals for filling.
If the system contains some dirt, flush it as described in
this section. If it is exceptionally dirty, the pump must be
completely disassembled before further usage. (The
steering unit cannot be disassembled.)
All tubes, hoses, and fittings should be inspected for
leakage at regular intervals. Fittings must be tight. Make
sure the clips, clamps and supporting tubes and hoses
are in place and properly secured.
Power steering hoses and lines must not be twisted,
kinked or tightly bent. Air in the system will cause
spongy action and noisy operation. W hen a hose is
disconnected or when fluid is lost, for any reason, the
system must be bled after refilling. Refer to Bleeding the
Power Steering System in this section.
・ Inspect gear for looseness or damage.
・ Inspect hoses to insure they are not touching an
y
other parts of the vehicle.
・ Inspect fluid level and fill to the proper level.

Fluid Level
1. Run the engine until the power steering fluid
reaches normal operating temperature, about 55 °
C (130 °F), then shut the engine off.
2. Check the level of fluid in the reservoir.
3. If the fluid level is low, add power steering fluid as
specified in General Information to the proper level
and install the receiver cap.
4. W hen checking the fluid level after the steering system has been serviced, air must be bled from
the system. Refer to Bleeding the Power Steering
System in this section.

Bleeding the Power Steering System
W hen a power steering pump or unit has been installed,
or an oil line has been disconnected, the air that has
entered the system must be bled out before the vehicle
is operated. If air is allowed to remain in the powe
r
steering fluid system, noisy and unsatisfactory operation
of the system may result.

Bleeding Procedure
W hen bleeding the system, and any time fluid is added
to the power steering system, be sure to use only powe
r
steering fluid as specified in General Information.
1. Fill the pump fluid reservoir to the proper level and let the fluid settle for at least two minutes.
2. Start the engine and let it run for a few seconds. Do not turn the steering wheel. Then turn the engine
off.
3. Add fluid if necessary.
4. Repeat the above procedure until the fluid level remains constant after running the engine.
5. Raise and support the front end of the vehicle so that the wheels are off the ground.
6. Start the engine. Slowly turn the steering wheel right and left, lightly contacting the wheel stops.
7. Add power steering fluid if necessary.
8. Lower the vehicle, set the steering wheel at the straight forward position after turning it to its full
steer positions 2 or 3 times, and stop the engine.
9. Check the fluid level and refill as required.
10. If the fluid is extremely foamy, allow the vehicle to settle for a few minutes, then repeat the above
procedure.

Flushing the Power Steering System
1. Raise and support the front end of the vehicle off
the ground until the wheels are free to turn.
2. Remove the fluid return line at the pump inlet connector and plug the connector port on the pump.
Direct the line toward a large container to catch the
draining fluid.
3. W hile running the engine at idle, fill the reservoi
r
with new power steering fluid. Turn the steering
wheel in both directions. Do not contact or hold the
steering wheel to the wheel stops. This will cause
the pump to go to pressure relief mode, which ma
y
cause a sudden fluid overflow at the reservoir.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

POWER-ASSISTED STEERING SYSTEM 3B-13
Power Steering Unit Disassembled View

RTW 53BLF000401
Legend
(1) Tie-rod End
(2) Lock Nut
(3) Clip
(4) Bellows
(5) Band
(6) Tie-rod Assembly
(7) Oil Line
(8) Rack Bar
(9) Tab W asher
(10) Mounting Rubber
(11) Housing Assembly
(12) Dust Cover



BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

3B-14 POWER-ASSISTED STEERING SYSTEM
Disassembly
NOTE : The valve hosing is made of aluminum and care
should be exercised when clamping in a vise, etc.
to prevent distortion or damage.
For the left side, follow the same steps as right side.
1. Loosen lock nut and remove tie-rod end.
2. Remove clip and band, then remove bellows.
• Use a pair of pliers to open the clip. Slide the cliptoward the tie-rod end.





RUW 53BSH000401
• Remove band from the bellows by using
screwdriver.





RUW 53BSH000501


CAUTION :
For 4 ×
××
×
2 except High ride suspension models;
The band is not reusable. If removed, it must be
replaced with a new one.
Take care not to damage the bellows during band
removal.
For 4 ×
××
×
4 and 4 ×
××
×
2 High ride suspension models;
The band and bellows are not reusable. If removed,
they must be replaced with a new one.
3. Remove tie-rod assembly.
To remove, move the boot toward the tie-rod end, then remove tab washer.
4. Remove oil line, mounting rubber and dust cover.

Inspection and Repair
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found during inspection.
Check the following parts.
1. Tie-rod end
2. Lock nut
3. Clip
4. Bellows
5. Band
Tie-Rod End
If looseness or play is found when checked by moving
the end of ball joint at tie-rod end, replace tie-rod end.

Tie-Rod Assembly
If the resistance is insufficient or play is felt when
checked by moving the ball on the tie-rod, replace the
tie-rod assembly.

Rubber Parts
For 4 ×2 except High ride suspension models;
If wear or damage is found during inspection, replace
with new ones.
For 4 ×4 and 4 ×2 High ride suspension models;
Even if wear or damage is not found after removal,
replace with new ones.

Reassembly
1. Install mounting rubber and dust cover (If removed).
2. Install oil line. Torque: 12 N ⋅
⋅⋅
⋅
m (1.2 kgf ⋅
⋅⋅
⋅
m/104 lb ⋅
⋅⋅
⋅
in)


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

3B-18 POWER-ASSISTED STEERING SYSTEM
Power Steering Pump Disassembled View






RTW 63BLF000301
Legend
(1) Bolt
(2) Suction Pipe
(3) O-ring
(4) Shaft Assembly
(5) Oil Seal
(6) Front Housing
(7) O-ring
(8) O-ring
(9) Side Plate
(10) Rotor and Vane
(11) Cam
(12) Pump Cartridge Assembly
(13) O-ring
(14) Snap Ring
(15) Rear Housing
(16) Bolt
(17) Spring
(18) Relief Valve
(19) O-ring
(20) Connector
(21) Bush
(22) Pulley
(23) O-ring




BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

POWER-ASSISTED STEERING SYSTEM 3B-19
Disassembly
1. Clean the oil pump with solvent (plug the discharge
and suction ports to prevent the entry of solvent).
Be careful not to expose the oil seal of shaft
assembly to solvent.
2. Remove the bolt, suction pipe and O-ring.
3. Remove the connector, O-ring, relief valve and spring.
4. Remove the bolt, rear housing and O-ring.
5. Remove the snap ring.
6. Remove the shaft assembly.
7. Remove the oil seal.
CAUTION: When removing the oil seal, be careful
not to damage the housing.
8. Remove the pump cartridge assembly from the front housing.
9. Remove two O-rings.

Inspection and Repair
Make all necessary adjustments, repairs, and part
replacements if wear, damage, or other problems are
discovered during inspection.

Rotor
442RS002
Check that the groove in the vane is free from excessive
wear and that the vane slides smoothly. W hen part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.



Vane
442RS003
Sliding faces of the vane should be free from wear.
(Particularly the curved face at the tip that contact with
the cam should be free from wear and distortion). W hen
part replacement becomes necessary, the pump
cartridge should be replaced as a subassembly.

Cam
The inner face of the cam should have a uniform
contact pattern without a sign of step wear. W hen part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.

Side Plate
The sliding faces of parts must be free from step wear
(more than 0.01 mm (0.0004 in)), which can be felt b
y
the finger nail.
The parts with minor scores may be reused after lapping
the face.

Relief Valve
The sliding face of the valve must be free from burrs
and damage. The parts with minor scores may be
reused after smoothing with emery cloth (#800 or finer).

Shaft
Oil seal sliding faces must be free from a step wear
which can be felt by the finger nail. Bushing fitting face
must be free from damage and wear.

O-ring, Oil Seal, Snap Ring
Be sure to discard used parts, and always use new
parts for installation. Prior to installation, lubricate all
seals and rings with power steering fluid.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007